Ingesting gradually larger amounts of egg protein may wipe out the allergy in children, researchers found.

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Ingesting gradually larger amounts of egg protein can desensitize a high proportion of children with egg allergy, researchers have found.

Note that of the immune markers measured, small wheal diameters on skin-prick testing and increases in egg-specific IgG4 antibody levels were associated with passing the oral food challenge at 24 months.

Ingesting gradually larger amounts of egg protein may wipe out the allergy in children, researchers found.

After two years of oral immunotherapy, 28% of children in a randomized controlled trial passed an oral challenge and were able to eat eggs a year later, Wesley Burks, MD, of the University of North Carolina at Chapel Hill, and colleagues reported in the July 19 issue of the New England Journal of Medicine.

"This is a treatment that we think is safe, and we think might work, but it is not ready to be put into practice," Burks told MedPage Today and ABC News. "It sounds somewhat simple, taking small doses of egg in larger and larger quantities, but it is not something to be done at home or in the office."

Tania Mucci, MD, an allergist at Winthrop University Hospital, noted that there's currently only one treatment for food-allergic patients: avoidance.

"Oral immunotherapy for food allergy, if safe and standardized, would be the holy grail for food-allergic patients," Mucci said in an email to MedPage Today and ABC News. "Immunotherapy to grasses, trees, cat, and dog is curative in 75% of patients."

James Li, MD, PhD, chair of allergy and immunology at the Mayo Clinic in Rochester, Minn., cautioned that there's still a risk for allergic reactions during immunotherapy.

"A single 'failure' of oral immunotherapy for food allergy could potentially result in a serious, even life-threatening reaction," he said in an email to MedPage Today and ABC News, adding that careful patient selection will be important if the therapy eventually becomes clinically available.

Burks and colleagues conducted their randomized, controlled trial at five U.S. centers. They enrolled 55 children ages 5 to 11 who had egg allergy; 40 were assigned to oral immunotherapy, while 15 were given placebo.

They found that after 10 months of therapy, 55% of children who had oral immunotherapy passed the oral food challenge of 5 grams of egg white powder and were considered desensitized, compared with none of the children in the placebo group (P<0.001).

Among these 22 desensitized kids, 14 had no symptoms, seven had mild symptoms, and one had moderate throat discomfort. All symptoms resolved without treatment, the researchers said.

After 22 months, 75% of kids in the oral immunotherapy group passed a challenge of 10 grams of egg white powder. These 30 desensitized children then avoided all egg consumption for 4 to 6 weeks.

After that brief period of avoidance, 11 children (28% of the oral immunotherapy group) passed another oral food challenge and were considered to have sustained unresponsiveness (P=0.03 compared with placebo).

At 30 and 36 months, all of these children were able to eat egg as they pleased, with no adverse events -- though the researchers cautioned that they could lose their sustained unresponsiveness if they were to stop eating eggs.

Burks and colleagues found that wheal diameters on skin-prick testing and egg-specific IgG4 antibody were predictive of passing the oral food challenge at 2 years.

In regression analyses, median IgG4 antibodies at 10 months were higher in children who were desensitized at 22 and 24 months (P=0.005 and P=0.02, respectively), and reduced wheal size at 22 months correlated with sustained unresponsiveness at 24 months (P=0.005).

The researchers noted that adverse events were more frequent with oral immunotherapy, with most being oral or pharyngeal, occurring during the first 10 months of oral immunotherapy, and most often related to dosing. About 15% of the oral immunotherapy group dropped out because of allergic reactions -- but there were no serious adverse events, they wrote.

The study was limited because the children could have spontaneously outgrown their egg allergy, though that was unlikely given study inclusion criteria that predicted a low likelihood of outgrowing the allergy, the researchers wrote.

Burks' group has previously tested oral immunotherapy on milk and peanut allergy as well. They'd found that peanut-allergic children on 48 weeks of oral immunotherapy could eat about 20 peanuts compared with just 1.5 peanuts for those in a placebo group.

But Burks again cautioned that it will be at least 5 to 10 years before oral immunotherapy for these types of allergies will be used clinically.

"For oral immunotherapy to be recommended as a standard of care," the researchers wrote in the study, "it will be important to better define the risks of oral immunotherapy versus allergen avoidance, determine the dosing regimens with the most favorable outcomes, identify patients who are most likely to benefit from oral immunotherapy, and develop postdesensitization strategies that promote long-term immune tolerance."